The present invention relates to a correct answer displaying device for a manual multiplication practicing unit which uses no electric power.
A conventional correct answer displaying device for a multiplication practicing unit includes blocks arranged in matrix form. In each of the blocks, a plastic, dark-colored transparent plate is provided, on the front surface of which a multiplier, a multiplicand, and the multiplication symbol are indicated and on the rear surface of which is bonded a black sheet punched to show the correct answer. A white plate is disposed below the dark-colored transparent plate with a small space therebetween so that the correct answer can be observed through the dark-colored transparent plate when the learner pushes the block with his finger.
The above-described conventional correct answer displaying device is disadvantageous in that, since the block is pushed with the finger, it is rather difficult to observe the whole correct answer. Moreover, if the device is handled roughly, the restoring elasticity of the dark-colored transparent plate may be reduced.